Add Floor numeric algorithm (#493)

Author: Paulofalcao2002

Algorithms.Tests/Numeric/FloorTests.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Numerics;
+using Algorithms.Numeric;
+using NUnit.Framework;
+
+namespace Algorithms.Tests.Numeric;
+
+public static class FloorTests
+{
+    [TestCase(0.0, 0)]
+    [TestCase(1.1, 1)]
+    [TestCase(1.9, 1)]
+    [TestCase(1.0, 1)]
+    [TestCase(-1.1, -2)]
+    [TestCase(-1.9, -2)]
+    [TestCase(-1.0, -1)]
+    [TestCase(1000000000.1, 1000000000)]
+    [TestCase(1, 1)]
+    public static void GetsFloorVal<T>(T inputNum, T expected) where T : INumber<T>
+    {
+        // Act
+        var result = Floor.FloorVal(inputNum);
+
+        // Assert
+        Assert.That(result, Is.EqualTo(expected));
+    }
+}

Algorithms/Numeric/Floor.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Numerics;
+
+namespace Algorithms.Numeric;
+
+/// <summary>
+///     Perform floor operation on a number.
+/// </summary>
+public static class Floor
+{
+    /// <summary>
+    ///    Returns the largest integer less than or equal to the number.
+    /// </summary>
+    /// <typeparam name="T">Type of number.</typeparam>
+    /// <param name="inputNum">Number to find the floor of.</param>
+    /// <returns>Floor value of the number.</returns>
+    public static T FloorVal<T>(T inputNum) where T : INumber<T>
+    {
+        T intPart = T.CreateChecked(Convert.ToInt32(inputNum));
+
+        return inputNum < intPart ? intPart - T.One : intPart;
+    }
+}

README.md

@@ -75,6 +75,7 @@ find more than one implementation for the same objective but using different alg
     * [Decomposition](./Algorithms/Numeric/Decomposition)
       * [LU Decomposition](./Algorithms/Numeric/Decomposition/LU.cs)
       * [Thin Singular Vector Decomposition](./Algorithms/Numeric/Decomposition/ThinSVD.cs)
+    * [Floor](./Algorithms/Floor.cs)
     * [Greatest Common Divisor](./Algorithms/Numeric/GreatestCommonDivisor)
       * [Euclidean GCD](./Algorithms/Numeric/GreatestCommonDivisor/EuclideanGreatestCommonDivisorFinder.cs)
       * [Binary GCD](./Algorithms/Numeric/GreatestCommonDivisor/BinaryGreatestCommonDivisorFinder.cs)